Oven lining



July 22, 1930. I w, J, LAFFREY I 1,770,930 I OVEN LINING Filed March 18. 1926 Zlmnntoz m M Z Patented July 22, 1930 UNITED STATES PATENT OFFICE I WILLIAM J. LAIFREY, OF DETBOIT, MICHIGAN, ASSIGNOR TO CENTRAL ALIlOY STEEL CORPORATION, CANTON, OHIO, A CORPORATION OF NEWYORK OVEN LINING Application filed March 18,1926. Serial No. 95,787.

methods, preferably by passing the sheets through a bath of molten lead maintained at a temperature above the melting point of zinc, and then through a superincumbent' bath of molten zinc. The galvanized sheet as it leaves the pot is prevented from too rapid cooling by direct orindirect application of heat'from a flame or flames for a suitable length of time, due care being taken to apply, the heat asuniformly as possible over the surfaces of the sheet. Preferably, the rate of cooling of the hot coated metal is efiected bypredetermined gradations of temperature. The thus treated sheet has a remarkably adherent or tight coating, and can be sub-' mitted to the usual bending and forming operations without cracking the coating.

I have further discovered that these sheets have the property of being remarkably resistant to high temperatures and to corrosion from fumes, and it is this property which makes the sheets as above described particularly suitable for oven linings 1n gas-stovesand other like locations.

I have illustrated in the accompanying drawing one of the more important uses of these sheets. .The single figure is a perspective view of an oven provided with a lining of the aforementioned sheets.

An oven at is shown with all of its walls lined with sheets a of the heat, smoke, and fume resisting material. .A door 6 is provided for closing the open side of the oven and has a lining d of the same material as the wall lining. It can be seen that the oven is completely lined with the resistant material and no deterioration of the oven walls can take place. 1

Long continued tests have shown that these sheets will withstand almost indefinitely the action of the heat, smoke and fumes in an oven in which cooking is conducted, without substantial impairment or peeling of the coating.

Thus these sheets after being subjected in a gas range to the steam and fumes from a strong salt water solution for 8 or 9 hours a day for 21 days (a test more severe than two years of household use) were found to. be

satisfactorily resistant.

The sheets produced by the delayed, cooling, as above described, can be given a dull or matte surface coating substantially free from the spangles characteristic of rapidly cooled galvanized sheets.

. By a thin coating I mean that the com-.

bined weight of the coatings applied to both sides of the sheet is not more than from about 0.3 to 1.25 ounces per square foot. A coating containing about an ounce or less per square foot is usually sufficient.

As is' well known, the coatings obtained on iron or steel sheets passed through a zinc bath are composed of a layer of zinc-iron alloys between the base sheet and the outerlayer which may be substantially zinc.

Microscopic examination of sections of the same. sheet, one portion-of whose surface was spangled and another portion having the fine grained or matte surface, has disclosed that the thickness of alloyed material, which term is used to apply to any compound or solid solution of zinc and iron existing as a discretelayer is practically the same in the brightly spangled and in the matte surface material. This zinc layer in the case of the dull gray or matte surface is only approximately one-half as thick as in the case of the spangled material. This condition is not dependent, as far as I am aware, upon the percentage of iron in the coating. The

controlling factor in the production of my improved plate, I believe to be the rate of cooling.

I claim: I

1. The combination with an oven of an oven lining sheet comprising a sheet of galvanized iron or steel having a closely adherentthin coating applied by galvanizing in the manner described, said coating being a resistant to heat smoke and fumes, and havv ing-a matte surf ace extending with substantial uniformity over the surface of the sheet.

2. In combination, a gas oven, and a, lining therefor comprising sheets of galvanized iron, each sheet having a closely adherent, malleable, thin sheet of zinc and zinc-ironv alloy, said coating having a matte surface and being resistant to heat,-smoke and fumes.

3. The combination with an oven, of

means for preventing the deterioration of the oven walls comprising a lining for said walls includin sheets of galvanized iron in which the coating consists of a malleable film of-zinc-iron alloy and zinc, said film being resistant to all of the deteriorating agencies developed in said oven.

In testimony whereof, I afiix my signature.

' WILLIAM J. LAFFREY. 

